Whether to put 'the’ in front of any English noun will never, ever let you go… Please hope, as a translator, that your clients don’t notice ‘whether to put in 'the' or not in front…’ of anything is a problem.
It’s true, I drew too thick a line in the sand and … every English noun needs an article should have gone on to say in the context of your sentence and the nouns and articles in it…
Discussing this with speakers of at least 18 other languages I realise it can be hard for non-natives to see why we use articles and that’s wholly beside the point. We do, so you must. That’s partly why https://learnenglish.britishcouncil.org/en/english-grammar/determiners-and-quantifiers/definite-article says The definite article the is the most frequent word in English.
It still sounds like A charity organization established overseas must submit the following documents to Ethiopian embassy located in the particular country or an acknowledged country is not the original, in any language. That looks like either government rules or government or charity guidelines, in which case it should make no distinction between A charity… established overseas… and one still trying to establish itself overseas. In that context, something like A charity… working overseas would be appropriate but the meaning is different.
… the particular country is wholly comprehensible and it isn’t, strictly, correct.
To make it so would mean going back to A charity organization working in a/any particular country must submit… in that (particular) country or …
… an acknowledged country is wholly comprehensible and it isn’t, strictly, correct. Nothing to do with the grammar, but a phrase like that in an official document really should be an accredited country or better, a country whose embassy is accredited for that purpose. Of course in grammar, these points are tiny and in terms of whether the traveller goes to gaol for a long time they make a huge difference.
If what you were given was A charity organization established overseas must submit the following documents to Ethiopian embassy located in the particular country or an acknowledged country then sorry: you need to point out to the client that that simply will not work in English.
Sorry but neither that translation nor anything it could obviously come from could work.
Whether it worked in general or not, the mismatch of nouns and articles does not work.
Coming back to the line in the quick-sand, you are talking about a wholly different part of the language which has no place here.
Never having met or even heard of a 'zero article' I had no idea what it might be until https://www.thoughtco.com/zero-article-grammar-1692619
There, some defence of zero article is an occasion in speech or writing where a noun or noun phrase is not preceded by an article (a, an, or the). Also called zero determiners seems well matched by … it is a linguistic myth that can now be safely retired and need no longer clutter grammatical descriptions.
Google couldn’t help with an occasion in speech or writing, either and still, those guys seem to be referring solely to abstract nouns, which is to say concepts rather than things. Perhaps like being shot by a zero bullet rather than being missed…
It - just - might be that English has room for a more refined distinction between types of abstract noun and still, that would have no place here.
Sorry again and Ethiopian embassy needs an article in the example; that still needn’t be the.